1. Field of the Invention
The present invention relates to an effective utilization of industrial waste and more specifically to a method of producing esthetically pleasing ornaments from bone components, in which carbon components in bone components are gasified and plasma-processed and the etching effect of hydrogen atoms is utilized to form thin diamond-like carbon (DLC) film on the surface of the base material.
2. Description of the Related Art
Traditional processes in the meat industry and medical industry produce large quantities of animal bones, some of which are incinerated as waste. As shown in the patent literatures listed below, waste animal bones produced from the meat industry are partially dried, crushed and mixed with powders made from dried organs, etc., to be utilized as condiments and other food materials.
Since waste animal bones contain a lot of calcium, phosphate and potassium, they are also made into ash and used as a component of fertilizer for promoting the growth of plant roots and blooming of flowers. Although waste bones are utilized effectively as explained above, the absolute supply quantity is huge and not all waste bones are effectively utilized. As a result, there has been a need for new applications in which they can be utilized effectively.
As described above, animal bones are utilized in numerous fields, main examples of which include: feeds such as animal feeds (as disclosed in Japanese Patent Laid-open Nos. 2004-49178 and Hei 10-117702) and nutrition-enriched feed compositions (as disclosed in Japanese Patent Laid-open Nos. 2003-199510 and 2000-4802), fish farming feed (as disclosed in Japanese Patent Laid-open No. 2003-18965), and chicken farming feeds (as disclosed in Japanese Patent Laid-open Nos. 2002-171917 and Hei 6-178655); applications for reinforcing bones and promoting bone growth such as bone-formation accelerators and fortifiers (as disclosed in Japanese Patent Laid-open Nos. 2004-231616, 2001-302539, Hei 10-298082 and Hei 9-227403), and composition for prevention of bone mass reduction (as disclosed in Japanese Patent Laid-open No. 2000-247896); and condiments such as meat and bone meal (as disclosed in Japanese Patent Laid-open No. 2003-116468). Examples for medical use include artificial bones (as disclosed in Japanese Patent Laid-open Nos. 2001-346818, 2004-269333, Hei 7-048109 and Hei 5-294752), improvement of bone adhesion (as disclosed in Published Japanese Translation No. 2001-525718 of PCT International Patent Publication No. WO99/45979 and Japanese Patent Laid-open No. Hei 10-234843), bone implant materials (as disclosed in Japanese Patent Laid-open Nos. Sho 62-053663 and Sho 59-211447), and composite biomaterial intended for dental cement (as disclosed in Japanese Patent Laid-open No. 2001-309970). The applications for agricultural, forestry and medical uses are limited to those in which enzymes and proteins contained in bones are utilized, and in the area of industrial chemical processes only applications as sintered abrasives and sliding members (as disclosed in Japanese Patent Publication (Examined) No. Hei 7-075831 and Japanese Patent Nos. 3121274 and 3590992) are known. Presently, animal bones are rarely used as functional materials.
Related art references in this case are as follows:
Japanese Patent Laid-open No. 2004-49178
Japanese Patent Laid-open No. Hei 10-117702
Japanese Patent Laid-open No. 2003-199510
Japanese Patent Laid-open No. 2000-004802
Japanese Patent Laid-open No. 2003-018965
Japanese Patent Laid-open No. 2002-171917
Japanese Patent Laid-open No. Hei 06-178655
Japanese Patent Laid-open No. 2004-231616
Japanese Patent Laid-open No. 2001-302539
Japanese Patent Laid-open No. Hei 10-298082
Japanese Patent Laid-open No. Hei 09-227403
Japanese Patent Laid-open No. 2000-247896
Japanese Patent Laid-open No. 2003-116468
Japanese Patent Laid-open No. 2001-346818
Japanese Patent Laid-open No. 2004-269333
Japanese Patent Laid-open No. Hei 07-048109
Japanese Patent Laid-open No. Hei 05-294752
Published Japanese Translation No. 2001-525718 of PCT International Patent Publication No. WO99/45979
Japanese Patent Laid-open No. Hei 10-234843
Japanese Patent Laid-open No. Sho 62-053663
Japanese Patent Laid-open No. Sho 59-211447
Japanese Patent Laid-open No. 2001-309970
Japanese Patent Publication (Examined) No. Hei 07-075831
Japanese Patent No. 3121274
Japanese Patent No. 3590992
On the other hand, the remarkable advancement of various industries of late has made it possible to use in many fields a number of composite materials combining the advantages of multiple materials including various metal materials, plastics and other organic polymer materials and other inorganic materials. Regarding these composite materials, surface reforming, or surface treatment of base material, is one of the technology areas that are drawing the most attention. Surface reforming can be implemented by adding chemical resistance, durability, wear resistance, hardness and other properties directly to the surface of conventional materials that already offer excellent machinability and are thus used in various industries. However, there are still a great number of materials that cannot be utilized, because they do not provide function suitable for the intended application or cannot demonstrate their natural function after surface reforming.
For this reason, there is a view that these materials can be used in greater applications once these drawbacks are improved, and therefore technologies to form thin diamond-like carbon (DLC) film, which is expected to improve durability such as chemical resistance, hardness and wear resistance, are drawing the attention and being applied in many fields. However, such applications also present concerns regarding the adhesion of thin film and various base materials as well as the level of achieved durability, and many study results have been reported regarding these issues. For example, thin DLC film is likely effective in medical device applications that make up a large market for technologies to form thin DLC film, because conventional medical devices do not provide sufficient compatibility or antithrombotic effect with respect to human body tissues such as blood and interior walls of blood vessels. Also, there are studies showing that thin DLC film containing fluorine can further improve the antithrombotic effect and lubrication property of catheters and implant-type medical devices. If such DLC can be formed more cost-effectively, DLC applications should expand further.